To enhance circulation in a person's feet, periodic or cyclic compression of tissue, such as the plexus regions of the foot, at predetermined timed intervals is beneficial. Under normal circumstances, blood moves up the legs due to muscle contraction and general movement of the feet or legs, such as when walking. If a person is immobilized, or has poor circulation brought on by disease, the natural blood return mechanism is impaired, and circulatory problems such as ulcers, deep vein thrombi, and pulmonary emboli can occur.
To mitigate these problems, it is desirable to concentrate a compressive force against veins in the feet. Current systems are primarily based on pneumatic compression devices that squeeze the calf.
In various current devices, tethered air lines limit mobility. Users cannot walk with them.